Over the last half century the automotive industry has, initially slowly, and subsequently with great rapidity, been evolving from mechanical control systems for controlling a vehicle's functions to electronic “drive by wire” control systems for controlling the functions. In mechanical vehicular control systems a driver of a vehicle controls components of a vehicle that control vehicle functions by operating mechanical systems that directly couple the driver to the components via mechanical linkages. In drive by wire vehicle control systems a driver may be coupled directly, and/or very often indirectly, to vehicle control components that control vehicle functions by electronic control systems and electronic wire and/or wireless communication channels, rather than direct mechanical linkages. The driver controls the control components by generating electronic signals that are input to the electronic control systems and the communication channels.
Typically, a vehicular electronic control system comprises a user interface for receiving driver actions intended to control a vehicle function, transducers that convert the actions to electronic control signals, and a plurality of sensors and/or actuators that generate signals relevant to the function. An electronic control unit (ECU) of the control system receives the user generated signals and the signals generated by the sensors and/or actuators, and responsive to the signals, operates to control a vehicle component involved in performing the function. The ECU of a given control system may also receive and process signals relevant to performance of the function generated by, and/or by components in, other vehicle control systems. The sensors, actuators, and/or other control systems communicate with each other and the ECU of the given control system via a shared in-vehicle communication network, to cooperate in carrying out the function of the given control system.
By way of example, a vehicle throttle by wire control system that replaces a conventional cable between an accelerator pedal and an engine throttle may comprise an electronic accelerator pedal, an ECU also referred to as an engine control module (ECM), and an electronic throttle valve that controls airflow into the engine and thereby power that the engine produces. The electronic accelerator pedal generates electronic signals responsive to positions to which a driver depresses the pedal. The ECM receives the accelerator pedal signals, and in addition electronic signals that may be generated by other sensors, actuators, and electronic control systems in the vehicle that provide information relevant to the safe and efficient control of the engine via an in-vehicle communication network. The ECM processes the driver input signals and the other relevant signals to generate electronic control signals that control the throttle. Among the other sensors actuators, and electronic control systems that may provide relevant signals to the ECM over the in-vehicle network are, air-flow sensors, throttle position sensors, fuel injection sensors, engine speed sensors, vehicle speed sensors, brake force and other traction control sensors comprised in a brake by wire system, and cruise control sensors.
In-vehicle communication networks of modern vehicles are typically required to support communications for a relatively large and increasing number of electronic control systems of varying degrees of criticality to the safe and efficient operation of the vehicles. A modern vehicle may for example be home to as many as seventy or more control system ECUs that communicate with each other and sensors and actuators that monitor and control vehicle functions via the in-vehicle network. The ECU' s may, by way of example, be used to control in addition to engine throttle described above, power steering, transmission, antilock braking (ABS), airbag deployment, cruise control, power windows, doors, and mirror adjustment. In addition, an in-vehicle network typically supports on board diagnostic (OBD) systems and communication ports, various vehicle status warning systems, collision avoidance systems, audio and visual information and entertainment (infotainment) systems and processing of images acquired by on-board camera systems. The in-vehicle network in general also provides access to mobile communication networks, WiFi and Bluetooth communications, TPMS (tire pressure monitor system) V2X (vehicle to vehicle communication), keyless entry system, the Internet, and GPS (global positioning system).
Various communication protocols have been developed to configure, manage, and control communications of vehicle components that are connected to and communicate over an in-vehicle communication network. Popular in-vehicle network communication protocols currently available are CAN (control area network), FlexRay, MOST (Media Oriented Systems Transport), Ethernet, and LIN (local interconnect network). The protocols may define a communication bus and how the ECUs, sensors, and actuators, generically referred to as nodes, connected to the communication bus, access and use the bus to transmit signals to each other.
The growing multiplicity of electronic control systems, sensors, actuators, ECUs and communication interfaces and ports, that an in-vehicle communication network supports makes the in-vehicle communication network, and the vehicle components that communicate via the communication system, increasingly vulnerable to cyber attacks that may dangerously compromise vehicle safety and performance.